Flatiron



Sept. 25, 1945. J. R. CAMPBELL FLATIRON Filed June 29, 1945 Inventor: James R. Campbell,

a 41% His Attorneg.

Patented Sept. 25, 1945 estates FLATIRON James R. Campbell, Ontario, Calii' asslgnor to General Electric Company,

New York a corporation of Application June carers, Serial No. 492,693

2 i'llalrns.

static means.

In accordance with this invention in one term thereof, a thermostatic member is situated close to the soleplate so as to respond to its temperature. This member is constructed and arranged to control the heating unit of the soleplate so as to control the temperature held in the soleplate. Auxiliary means are provided for supplying heatto the thermostatic member in addition to that been shown in one form as applied to an electrically heated flatlron comprising a pressing soleplate it, a shell it above the soleplate, and a handle it fastened to the shell. The soleplate it is heated by an electrical heating element it,

supplied to it from the soleplate. This auxiliary it ofi from the soleplate thermostat. By adjust= I ing the action of the remotely situated thermostat, the amount of auxiliary heat supplied to the scleplate .rerruostat is controlled, and hence the temperature of the soleplate itself is corrtrolled. This is because the amount of heat supplied by the soleplate to cause the action oi its thermostat will depend upon the amount or auxiliary heat supplied. Thus, a low s'oleplate temperature results when a relatively great amount oi. auxiliary heat is applied to the solcplate thermostatby the auxiliary heater, and a high soleplate temperature results when arelatively small quantity of heat .is applied by the auxiliary heater.

For a more complete understanding or this invention, reference should be had to the accompanying drawing in which Fig. l is a side elevation, mainly in section illustrating a flatiron embodying this invention; and Fig. 2 is. a dis. grammatic representation of the heating means for the flatiron and the temperature control means provided for its embodying this invention.

Referring to the drawing, this invention has which preferably will be of the sheathed type comprising an outer sheath it housing a helical resistance conductor it, and which conductor held in spaced relation with reference to the sheath by a highly-compacted mass ill of heat conducting, electrically insulating material, such as powdered magnesium oxide. Preferably, the heating element 113 will be cast in the soleplate ill-as shown.

As shown diagrammatically in Fig. 2, the heat ing element is will be energized from a suitable electrical source of supply ll. Interposed in the energizing circuit of the heater it which connects it with the supply source is a suitable control switch it comprising a pair of spaced fixed contacts l9 and a movable bridging contact Eat, the parts being arranged so that when the bridging contact is in its open position the heating element I33 is deenergized, Whereas when it is in its closed position the heating element is energized.

The operation of the bridging contact 2U! he= tween its closed and open positions is effected by means of a bimetallic temperature responsive element it which. is in the form of an elongated her having its left-hand end, as viewed in the drawing, rigidly secured to the soleplate in direct thermal relation with it as by means of a clamping member 22. The remainder of the bar is free to move responsively to temperature changes, and the free end thereof carries. an actuating support 22a for the bridging contact to, as shown. It will be understood that a bimetallic bar of this nature is formed by securing two pieces oi metal together lengthwise from end to end, the two pieces having difierent thermal coefficients or expansion so that'the bar moves up and downwlth reference to the soleplate as its temperature changes. The bar illustrated curves upwardly, as viewed in Fig. 1, as its temperature is elevated andcurves downwardly when its temperature is reduced.

In addition to the heat which the bar 2i re ceives from the soleplate, I provide an auxiliary heating means 23 for applying heat to the bar. This auxiliary heating means is in the form of a resistance conductor wound directly on the bar, but electrically. insulated from it by any suitable means (not shown). a

'The energization of this auxiliary heater 23 is controlled by means or .a thermally responsive device 24 remotely situated. with reference to the soleplate. In the specific example shown in Fig.

i, it is mounted in the handle 12. This handle 52 preferably will be formed of a suitable phenolic condensation product; and preferably, a suitable 5 heat baflie 25 will beinterposed between the forward end of the shell and the forward standard of the handle, while the rear standard also preferably will have a small heat contact with the shell. The hand grip portion of the handle, as shown, is hollow and in. this hollow section wardly and when cooled curves' upwardly. The

free end of this bar carries a contact 27 which coacts with an adjustable contact 28 shown in the form of a screw mounted inthe handle above the contact 2?, and the bar is normally flexed upwardly so as to bias the contact 27 into enagement with the contact 28. This bar also is provided with local heating means, but here, the bar constitutes its own heater-being heated by its resistance to the passage of current, rather than being heated by a separate heater. 30

- 28 controls the quantity of current supplied to The various elements of the control are connected as shown diagrammatically in Fig. 2.

Preferably, the rear standard of the handle will be hollow, as well as the hand-gripping part, and

the connections between the supply source .and

the heating element and also those between the auxiliary heater 23 and the remotely situated thermal control element 2 3 will be directed through the hollow handle, as shown.

In the operation of the system, it will be understood that when the iron is plugged in" to the supply source Ill, the switch it and the control switch El, 28 initially will be closed. Therestore, when theiron is plugged in, the heating element it will be energizedby a circuit which may be traced from the upper conductor of the supply source (Fig. 2) throughthe heating element, and thence through theclosed contacts it to the lower conductor of the supply source ll. 1 Also, the auxiliary heater 23. will be ener- 5 gized through. contacts 21 and 28 from the sup-.- ply source. Therefore, the thermal bar 2! will" receive heat both from the soleplate It and from the auxiliary heater 23, and when its tempera ture attains a predetermined high value it will Linember positioned within said'chamber of said handle out of the thermal influence of said soleplate and operative to control said auxiliary heat switch it sees to reenergize the heating ele- 6.

open the bridging contact 20 to deenergize the soleplate heating element I3; the soleplatethereupon will cool down and ultimately permit'th'e thermostat 2i to cool sufiiciently to reclose the merit to.

The high temperature thatthe soleplate iii attains before heating the thermostat ii to open its energizing circuit will, of course, depend upon the amount of auxiliary heat supplied by the heater 23. If this heater supplies a great quantity of heat, then but a very small amount will be supplied by the soleplate I0 beforethe energizing circuit of the iron isope'ned, and consequent- 7o ly, the soleplate operating temperature will be relatively lowi whereas if but a very small amount of'heatbe supplied bythe auxiliary heater 23, then a greater quantity of heat has to be sup- The right-hand end of i5 thermostat and the soleplate operates at a higher temperature.

The amount of heat supplied by the auxiliary heater 23 is controlled ,by the opening and closing actions of the thermostat 26, and this operation depends upon its heating due to its own resistance to the flow of current in the circuit of the auxiliary heater 23. In other words, when the circuit through the thermal element '26 is completed, thereafter in a predetermined interval of time it will function to open the switch contacts 27! and 28 and thereby open and deenergize the auxiliary heater 23; following this the element 26 will cool down and reclose the contacts El and 28 in order to reenergize the .heater 23. The proportion of time that energy them open. This latter operation is controlled by adjusting the position of the fixed contact 28; if this contact 28 be moved upwardly, the proportiorfoi time that heat is on is reduced, whereas if it be adjusted downwardly, the proportion of time heat is on is increased. In other words, the adjustment of the-fixed contact the auxiliary heater 23 in a given period of time. If this quantity is increased, the soleplate will operate at a lower temperature, whereas if it is reduced the soleplate will operate at a higher temperature.

While I have shown a, particular embodiment .of my invention, it will be understood, of course, that I do not wish to be limited thereto since many modifications may be made, and I, therefore, contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is: K

l. A fiatiroii comprising a soleplate, a handle I for operating said soleplate having a chamber.

therein thermally remotely situated with reference to said soleplate, a heating unit for applying heat to said soleplate, a thermally responsive member responsiveto the temperature of said soleplate controlling said heating unit to control the temperature of said soleplate, auxiliary means for heating said temperature responsive member, a second temperature responsive ing means, and means for heating said second temperature responsive member controlled by it so that it alternately applies heat to and cuts ofi heat from said membentaidsecond temperature responsive member thereby controlling said auxiliary heating means alternately to supply heat to and cut'it 05 from said first-named templied by the soleplate in order to actuate the 7s bimetallic element in thermal relation w h Sai assaeoe soleplate. switching means controlled by said bimetallic element for controlling the energization of said heating element to hold a substantially constant temperature in said soleplate, an auxiliary heater for applying heat to said bimetallic element in addition to the heat which is supplied to it from said soleplate, and a control device for said auxiliary heater located within said handle, comprising a second bimetallic element,

\ switch means operated by said second bimetallic element, an energizing circuit Ior said auxiliary heater, independent of the circuit of said soleplate, and including said switch means, heating means controlled by said second bimetallic element for heating it to a predetermined high temperature to open said switch means to deenergize said circuit and shut 03 said heating means, and said'second bimetallic element then cooling to reclose said switch means to reenergiz'e said circuit and operate said heating means to again apply heat to it, said second thermostatic element thereby controlling the amount of heat energy supplied by said auxiliary heater to said first bimetallic element, and means for adjusting the switch means operated by said second bimetallic element in order to vary the proportion of time that heat is supplied by said auxiliary heater to said first bimetallic element to the time that heat is not supplied so as to vary the temperature setting 0! said first bimetallic element. JAMES R. CAMPBELL. 

